- The child must have been born at less than or equal to 35 weeks gestation and be less than or equal to 6 months of age at the time of entry into the study (child must be entered on or before his/her 6-month birthday); or the child must be less than or equal to 24 months of age at the time of entry into the study (child must be entered on or before his/her 24-month birthday) and diagnosed with chronic lung disease (CLD) of prematurity with stable or decreasing doses of diuretics, steroids, or bronchodilators, or treatment with supplemental oxygen, within the previous 6 months.